Unspecified vulnerability in Cisco IOS 12.0 through 12.4 allows remote attackers to execute arbitrary code via a malformed SIP packet, aka CSCsi80749.

Buffer overflow in the Next Hop Resolution Protocol (NHRP) functionality in Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (restart) and execute arbitrary code via a crafted NHRP packet.

Cisco IOS 12.4 and earlier, when using the crypto packages and SSL support is enabled, allows remote attackers to cause a denial of service via a malformed (1) ClientHello, (2) ChangeCipherSpec, or (3) Finished message during an SSL session.

The FTP Server in Cisco IOS 11.3 through 12.4 does not properly check user authorization, which allows remote attackers to execute arbitrary code, and have other impact including reading startup-config, as demonstrated by a crafted MKD command that involves access to a VTY device and overflows a buffer, aka bug ID CSCek55259.

The Intrusion Prevention System (IPS) feature for Cisco IOS 12.4XE to 12.3T allows remote attackers to bypass IPS signatures that use regular expressions via fragmented packets.

The ATOMIC.TCP signature engine in the Intrusion Prevention System (IPS) feature for Cisco IOS 12.4XA, 12.3YA, 12.3T, and other trains allows remote attackers to cause a denial of service (IPS crash and traffic loss) via unspecified manipulations that are not properly handled by the regular expression feature, as demonstrated using the 3123.0 (Netbus Pro Traffic) signature.

Cisco IOS after 12.3(14)T, 12.3(8)YC1, 12.3(8)YG, and 12.4, with voice support and without Session Initiated Protocol (SIP) configured, allows remote attackers to cause a denial of service (crash) by sending a crafted packet to port 5060/UDP.

Cisco IOS 9.x, 10.x, 11.x, and 12.x and IOS XR 2.0.x, 3.0.x, and 3.2.x allows remote attackers to cause a denial of service or execute arbitrary code via a crafted IP option in the IP header in a (1) ICMP, (2) PIMv2, (3) PGM, or (4) URD packet.

Memory leak in the TCP listener in Cisco IOS 9.x, 10.x, 11.x, and 12.x allows remote attackers to cause a denial of service by sending crafted TCP traffic to an IPv4 address on the IOS device.

Cisco IOS allows remote attackers to cause a denial of service (crash) via a crafted IPv6 Type 0 Routing header.